10 most interesting showdowns in 2010

With a combined total of more than 500 House, Senate and gubernatorial races next year, it’s hard to cut through the spin to figure out which ones are worth watching. Here is POLITICO’s list of 10 contests to keep an eye on, whether it’s because they are uniquely revealing, particularly significant — or simply impending train wrecks.

But it’s still likely to be the marquee race of 2010. This high-stakes contest will be drenched in national money, and both parties will stop at nothing to achieve their desired outcome.

All the polling in the race signals that Reid is in serious trouble, but that doesn’t mean there’s no clear path to reelection for the four-term Democratic incumbent. A handful of Republicans are vying for a chance to take him on, but the GOP struggled to come up with a well-known, top-tier opponent. That may be because Reid is widely recognized as a fierce opponent, and he’ll have all the money he needs to run the campaign he wants.

Pennsylvania Senate

No incumbent in the House or Senate has a longer or tougher road to reelection than Democratic Sen. Arlen Specter.

First, there’s a primary against Rep. Joe Sestak, a tenacious and well-funded campaigner who is challenging Specter’s Democratic credentials. Then comes a grueling general election against former Republican Rep. Pat Toomey, another well-funded and experienced candidate who’s already run against Specter before — he narrowly lost to Specter in a 2004 GOP primary.

Specter doesn’t exactly cultivate a warm and fuzzy image, so don’t expect either Sestak or Toomey to pull their punches. And as a party switcher, Specter is going to face withering attacks on his character.

In his corner, however, are two formidable allies: the White House, which has an interest in sending a message to prospective party switchers, and the Democratic establishment in Pennsylvania.

Florida Senate

The Republican primary here between Gov. Charlie Crist and former state House Speaker Marco Rubio is likely to be more interesting than the general election.

Tea party activists have already signaled that they view this race as the next N.Y. 23, the Nov. 3 special election where the conservative grass roots revolted against the GOP establishment’s candidate.

Crist, whose poll ratings have lagged recently, is a prolific fundraiser and a skillful retail campaigner. But a February event with President Barack Obama during which he embraced the stimulus package has turned into an albatross in his bid for the nomination.

Rubio, a talented candidate in his own right, has every intention of reminding Republicans of Crist’s heresy, giving this contest all the makings of a GOP civil war.

Illinois Senate

In the GOP primary, front-runner Rep. Mark Kirk faces resistance from conservatives. In the Democratic primary, front-runner state Treasurer Alexi Giannoulias has not yet won over his own party.

While the February primary — the earliest in the nation — will settle all those questions and leave plenty of time for healing, there are several other X factors that make this race so compelling.

There’s impeached Democratic Gov. Rod Blagojevich, whose shenanigans threw this seat into play — he’s slated to go to trial next year. You can bet it will be a circus that will not reflect favorably on Illinois Democrats.

Then there’s the Chicago mafia in the White House — they aren’t about to give up the president’s old Senate seat without a fight.

Texas Governor

All the best action in this race will take place in the bitter GOP primary, in which Gov. Rick Perry faces a challenge from Sen. Kay Bailey Hutchison.

There is a deep reservoir of animosity between the two leading statewide Republicans, which means the race will be nasty, brutish and expensive.

Hutchison, one of the state’s most popular pols, has been slow out of the gate. And she hasn’t ever run a race quite like this one. Perry, on the other hand, is a veteran of smash-mouth contests, having won a 2002 campaign in which his Democratic opponent spent $67 million to his $28 million.

Ohio Governor

Ohio has been kind to Democrats in recent years, but the flailing state economy and an unemployment rate of 10.1 percent have threatened first-term Democratic Gov. Ted Strickland’s reelection prospects.